The present invention relates generally to devices for applying graphics to wearing apparel, and more particularly to a manually actuated heat press machine for use in applying heat transfers to wearing apparel and including an adjustment mechanism for selectively increasing or decreasing the level of compressive pressure exerted thereby.
It is a common practice in the wearing apparel industry to apply decals commonly referred to as heat transfers to various items of wearing apparel, and most notably T-shirts. Heat transfers typically comprise decorative indicia or ornamental matter in the form of a generally planar sheet which is either impregnated with a thermoset material or has such thermoset material applied to one side or face thereof. The application process is typically accomplished by placing the heat transfer onto the item of wearing apparel or other substrate. As will be recognized, if the heat transfer includes a layer of thermoset material applied to one side thereof, the side having the thermoset material applied thereto is placed into direct contact with the substrate. Thereafter, compressive pressure is applied to the heat transfer concurrently with a relatively high level of heat. The combination of heat and compressive pressure facilitates the adhesion of the heat transfer to the substrate.
During the application process, it is critical that the proper amount of compressive pressure be applied to the heat transfer. In this respect, if the level of applied compressive pressure is excessive, the typical result is that the heat transfer is smashed into the substrate. As will be recognized, such "smashing" in turn results in the irreparable distortion of the heat transfer, and consequently the ruining of the substrate due to the inability to remove the heat transfer therefrom. Conversely, if the level of applied compressive pressure is insufficient, the typical result is that the heat transfer does not properly adhere to the substrate. Such lack of adhesion usually results in the heat transfer peeling or falling off the substrate either immediately or shortly thereafter, such as during a laundry cycle.
There is currently known in the prior art various manual and automatic devices for facilitating the application of a heat transfer to a substrate. However, these prior art devices possess certain deficiencies which detract from their overall utility. More particularly, currently known manual devices typically lack the capacity to allow the level of compressive pressure applied to the substrate thereby to be selectively adjusted. Such adjustability is highly desirable in that the proper level of compressive pressure to be applied by the device is often a function of the thickness of the particular substrate to which the heat transfer is to be applied. Though some prior art manually operated devices include mechanisms to facilitate a pressure adjustment, such devices do not provide a way to accurately gauge the level of compressive pressure being applied thereby, with variances from machine to machine requiring that the operator of a particular machine learn the nuances thereof. These drawbacks are also found in prior art automatic devices, including those which are pneumatically controlled or operated.
The manually actuated or operated heat press machine described in the parent application addresses the short-comings of these prior art devices due to its inclusion of an adjustment mechanism for allowing the compressive pressure applied thereby to be selectively raised or lowered to a desired level with a high degree of accuracy during the process of applying a heat transfer to a substrate. Though providing numerous advantages over the prior art, Applicant has determined that there is a susceptibility for the upper platen of its heat press machine as described in the parent application to move forwardly relative to the lower platen when the actuation handle thereof is moved between its press and release positions. As will be recognized, such heat press machine of the Applicant would provide even greater advantages over prior art devices if the same were to be configured such that the upper platen thereof was maintained in substantial alignment with the lower platen at all times during the movement of the actuation handle between its press and release positions, since the forward movement of the upper platen upon the movement of the actuation handle to its press position could have an adverse effect on the process of applying the heat transfer to the substrate. The present invention addresses this further need by providing a linkage mechanism which is added to Applicant's heat press machine as described in the parent application and effectively maintains the upper platen in substantial alignment with the lower platen during movement of the actuation handle between its press and release positions.